PYONGYANG, March 22 (Bernama) -- U.S. President Donald Trump had written a "personal letter" to North Korean leader Kim Jong Un, Xinhua news agency quoted the state run Korea Central News Agency (KCNA) as saying Sunday, citing a senior official. Trump had "explained his plan to propel" relations between the United States and the DPRK and expressed his intention to render cooperation in the anti-epidemic efforts, said Kim Yo Jong, the first vice department director of the Central Committee of the Workers' Party of Korea. "We regard it as a good judgment and proper action for the U.S. president to make efforts to keep the good relations he had with our Chairman by sending a personal letter again at a time as now when big difficulties and challenges lie in the way of developing the bilateral relations, and think that this should be highly estimated," Kim as quoted by the KCNA as saying in a statement. However, relations between the DPRK and the United States as well as the development of bilateral ties should not be judged in haste in the light of the two top leaders' personal relationship, she said, warning against drawing hasty conclusions and setting unrealistic expectations. "If impartiality and balance are not provided and unilateral and greedy intention is not taken away, the bilateral relations will continue to aggravate," she said. Denuclearization talks between Pyongyang and Washington have stalled since the top leaders of both sides failed to reach an agreement during their second summit in Hanoi, Vietnam, in February last year.